I have a huge problem. Again I bent my rear mech cage ad repaired it a little, but I also bent mech hanger. I have XC bike and i think i'm a little too aggressive for it. Are there any solutions accept buying freeride or dh or 4X bike w/ short cage rear mech?
Many bikes have weak derailleur hangers, so I wouldn't isolate the issue to your bike being an XC bike. Are you bending it by hitting it on rocks on accident? or do you find it bent after a rough downhill section? If you're hitting it on rocks, a short cage might help, and you may be able to get away with it on your XC bike. It all depends on your front gearing and whether or not the capacity (meaning the total spread from your lowest to highest gear) of the new derailleur will match up.
Honestly, I don't know, I ride aggressively and I know I shouldn't on not so weak frame, but i plan on buying used DH bike for freeride and stuff. Anyway, where I ride it's mostly hard packed dirt trails, rough rock sections (tallest rock is maybe 4 inches) and loose rock . Although I might have hit it on a log on a side of trail. Yes, I have taught about short cage mech, but that is at least 200 - 300 dollars worth of chain, cassette, rear mech, chainrings... Cassette is 34 to 11 (I think), but I don't know front chain rings (I run 3 on a front, rarely using biggest).
You don't need to replace the chain, cassette, or chainrings if you can find a short cage derailleur with the same number of shifts as you currently have rear gears (likely 9 or 10-speed). It's easy to swap out. Given that you only use the smaller front two rings, it'll work.